He's intelligent enough to do it when he knows it's a free kick, like someone charging into the back of him. He's a threat and the opposition know it so they give him a kick and target him. Kane's another expert at winning free kicks for very little - but enough - contact. Ball fired into him, takes a touch, holds defender behind him then falls onto the ball - free kick.
Most of our players take one or two touches and keep the ball moving. De Bruyne is someone who takes a few more or looks to run with the ball to make things happen and as a result is fouled a lot.
There are definitely things Grealish can improve on, but that's two England games in a row now where the performances all round have been fairly poor but he's been involved in the goals. He opened Austria up with his little ball round the corner to Kane (who showed great movement), then split the defence looking to get on the end of the return ball.
And he showed good nous to get into the box and draw the foul for the penalty yesterday. Maybe it's overruled without VAR but there was some contact and as a defender if you are wrong side you are in trouble when trying to make a tackle or get back into position.